Gaming system with feature game play

ABSTRACT

The invention relates to gaming systems and methods of gaming. A game, which may be implemented in a gaming system ( 100 ) with a game controller ( 101 ), includes a base game and a feature game wherein during play of the base game, if a feature awarding event occurs, a player is awarded with an amount of feature credits (step  5 ), the feature credits usable to buy bets in the feature game (steps  6, 7 ). Use of the feature credits in the feature game is in response to inputs received from a player interface and a balance of feature credits is maintained as the feature credits are used.

RELATED APPLICATIONS

This application claims priority to, and is a continuation-in-part of, International Application No. PCT/AU2007/000034 having an International filing date of Jan. 16, 2007, which claims priority to Australian Patent Application No. 2006900239, filed Jan. 17, 2006. The '034 International Application is hereby incorporated by reference herein in its entirety.

The present invention relates to gaming systems with a feature game play function. In particular, but not necessarily exclusively, the present invention relates to gaming machines (including slot and fruit machines) that provide feature game play.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[Not Applicable]

MICROFICHE/COPYRIGHT REFERENCE

[Not Applicable]

BACKGROUND OF THE INVENTION

The huge success of gaming machines that provide feature games to a player has resulted in almost every video gaming machine having a feature game of some type. As technology, demand and gaming machine design expertise has increased, the feature games have become increasingly varied and more entertaining to players. To some extent, the feature games have also become increasingly sophisticated, while remaining simple to understand and operate in use.

There is a continuing need in the gaming industry to provide new and improved gaming systems that allow betting and provide player entertainment. However, the regulations in the relevant jurisdiction for the gaming venue may restrict the allowable variations on gaming machines. Therefore, gaming machine manufacturers continually attempt to design new gaming machines that are innovative and entertaining, while remaining within the bounds of the relevant regulations. In addition, a gaming system must be able to provide a reasonable return to a gaming venue operator.

One common feature provided on gaming machines is to provide a series of “free games”. For example, if the base game is a spinning reel game, the feature game may be a number of spins of the spinning reels without deducting credits from a credit meter or the player's account. In addition, during play of the feature game, the playing conditions may be varied, for example by substituting particular symbols on one or more of the spinning reels, or varying the amount paid on a win in order to provide an increased chance of winning a prize and/or an increase in the value of the prize payouts.

Another common feature game is to provide a series of games which must be purchased (a bought feature). For example, if the base game is a spinning reel game, the reels may produce an outcome which entitles the player to play feature games. The player is not obliged to play these games and can leave the machine at any time. The machine, however, remains in “feature” mode until the feature is complete.

Often, a feature game may be awarded to a player when a trigger event occurs in the base game. The trigger event may occur with a predetermined probability regardless of the size of a bet placed by the player. This creates a problem in maintaining a constant payout ratio across all bet sizes. One way to address this is to use the same bet in the base game as in the feature games. For example, if the player was playing three pay lines in a base game which triggered a feature game, then the player would be restricted to playing three lines in the free games. If the player played more or less lines in the triggering game, then a corresponding number of lines would be played in the free games. However, using this method in a bought feature locks the player into a certain size bet for the duration of the feature. If the player leaves the machine, the next player is then locked into the bet size that initiated the feature, which the Applicant believes may turn some players away from the gaming machine.

BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided a gaming system operable to play a game comprising a base game and a feature game, the gaming system comprising:

a game controller for controlling play of the game, the game controller awarding base game credits to a player in the event of a winning event during play of the base game and awarding a feature game and feature game credits on the occurrence of a feature awarding event during play of the base game,

at least one display to display representations of play of the game,

a player interface to enable the player to control at least some aspect of play of the base game and the feature game,

a main credit meter that maintains a record of the number of said base game credits available to play the base game,

a feature game credit meter that maintains a record of the number of said feature game credits available to a player to play the feature game, and

a selector that enables the player to select a wager in credits from a plurality of wager options of different values for play of the feature game, the selected wager being deducted from the feature credit meter, and

wherein the main credit meter is also deducted in response to play of the feature game.

The main credit meter may be deducted in response to play of the feature game by an amount of credits equal to the value of the wager selected for that play of the feature game.

The feature game may have an enhanced play characteristic in comparison to the base game. The enhanced play characteristic may be at least one of an enhanced pay out table and an increased chance of a win. Other methods of providing enhanced play may also be used.

The game controller may require play of the feature game and wagering of the feature game credits immediately following the award of the feature game. The player may, following the award of the feature game, be provided with the choice to either play the feature game or cash out.

The feature game credits may not be able to be cashed out and if a player cashes out and there is a positive balance of feature game credits, the gaming system may allow play of the feature game, including by a subsequent player of the game.

The number of awarded feature game credits may be a multiple of the bet made in the game play of the base game that caused the feature game to be awarded. The multiple may be between 10 and 30 inclusive. A plurality of different events may cause the award of a feature game and feature game credits and a plurality of different multiples of said bet made may be awardable, wherein the applicable multiple is dependent on the event that caused the award of the feature game.

The plurality of wager options may comprise wager options with a different number of bets and different amounts wagered per bet.

According to a second aspect of the present invention, there is provided a gaming system comprising a game controller for controlling play of a base game and a feature game, at least one display to display game play of the base game and the feature game, and a player interface to enable a player to control at least some aspects of play of the base game and the feature game, both the base game and the feature game resulting in the award of an award on the occurrence of a winning event for that game, wherein during play of the base game, if a feature awarding event occurs, a player is awarded with an amount of feature credits, the feature credits usable to buy bets in the feature game, wherein the gaming system controls use of the feature credits in the feature game in response to inputs received from the player interface and maintains a balance of feature credits as the feature credits are used, and wherein should more credits than the current balance of feature credits be required to play the feature game, credits are deducted from a second credit meter dependent on the difference between the required credits and the feature credits.

If credits are deducted from the second credit meter, then a modified award may be awarded, dependent on the proportion of the bet covered by feature credits.

According to a third aspect of the present invention, there is provided a gaming system comprising a game controller for controlling play of a base game and a feature game, at least one display to display game play of the base game and the feature game, and a player interface to enable a player to control at least some aspects of play of the base game and the feature game, both the base game and the feature game resulting in the award of an award on the occurrence of a winning event for that game, wherein during play of the base game, if a feature awarding event occurs, a player is awarded with an amount of feature credits, the feature credits usable to buy bets in the feature game, wherein the gaming system controls use of the feature credits in the feature game in response to inputs received from the player interface and maintains a balance of feature credits as the feature credits are used, and wherein should more credits than the current balance of feature credits be required to play the feature game, then an award resulting from that play of the feature game is modified.

The extent of modification may be directly dependent on the proportion of the bet covered by feature credits.

In at least the second and third aspects described above, the amount of feature credits awarded may be dependent on the value of a bet placed by the player in an activation of the base game that is causally linked to the award of the feature credits. The multiple may be between 10 and 30 inclusive.

In at least the second and third aspects described above, following award of the feature credits the gaming system may require immediate play of the feature game and require that all the feature credits are used before returning to the base game. The feature credits may not be able to be cashed out and the requirement to play the feature game until all the feature credits are used may continue when play of the game is recommenced following a player cashing out.

In at least the second and third aspects described above, the probability of occurrence of the feature awarding event may be independent of the size of a bet placed in an activation of the base game.

In at least the second and third aspects described above, the feature game may be a bought feature game. The base game and the feature game may have the same format and an equal number of credits may be deducted from a main credit meter as the number of feature credits bet in the feature game.

According to a fourth aspect of the present invention, there is provided a gaming system comprising a game controller for controlling play of a game comprising a base game and a feature game, at least one display to display game play of the game, and a player interface to enable a player to control at least some aspects of the game play of the game, both the base game and the feature game resulting in the award an award if a winning event occurs, wherein during play of the base game, if a feature award event occurs, a player is awarded with an amount of feature credits, the feature credits usable to buy bets in the feature game, wherein the feature game repeats over consecutive activations and for each said activation the game controller allows the player to control use of the feature credits in said feature game by operating the player interface.

The game controller may repeatedly activate the feature game until the feature credits have been exhausted and then returns to play of the base game.

The base game and the feature game may have the same screen format and have the same bet options.

According to a fifth aspect of the present invention, there is provided a gaming system adapted to play a game comprising a base game and a feature game, the gaming system comprising:

a game controller for controlling play of the game and adapted to award base game credits to a player in the event of a winning play on the base game and activating the feature game and awarding feature game credits on the occurrence of a triggering event during play of the base game, the feature game credits being at least sufficient to enable a plurality of activations of the feature game at a level of bet that was made in the base game when the triggering event occurred,

at least one display to display game play of the base game and the feature game,

a player interface to enable the player to control at least some aspect of the game play of the base game and the feature game,

a main game credit meter adapted to display the number of game credits available to a player to play the game,

a feature game credit meter adapted to display the number of feature game credits available to a player to play the feature game, and

a selector which, when a player is awarded a feature game by the game controller, enables the player to select the number of feature game credits to be bet on a play of the awarded feature game.

In one embodiment, the feature game must be played after the triggering event before the game controller controls the game to return to play of the base game and all the feature credits must be exhausted before the game controller allows play of the base game to resume.

The awarded feature game credits may be a predefined multiple of a bet made in the activation of the base game that caused the feature game to be awarded.

The selector may allow the player to vary the number of feature game credits to be wagered between successive plays of the feature game.

The player can vary the number of feature game credits to be wagered between successive activations of the feature game by varying at least one of the number of bets made in each said successive play and the amount wagered per bet.

In any of the aspects described above, the gaming system may offer an option to buy a bet in the feature game that has a value of one credit.

In any of the aspects described above, the gaming system may be a standalone or networked gaming machine.

According to a sixth aspect of the present invention, there is provided a method of gaming implemented using an electronic processing system, the method comprising using a computational controller to monitor for the occurrence of a feature awarding event during play of a base game and if a said feature awarding event occurs, awarding an amount of feature credits, and monitoring play of a feature game and decreasing said amount of feature credits dependent on play of the feature game, wherein the method further comprises allowing a player to specify the amount of the credits required to play an activation of the feature game, and if the number of credits required exceeds the number of feature credits available, deducting credits from a second credit meter dependent on the difference between the credits required and the feature credits that are available.

According to a seventh aspect of the present invention, there is provided a method of gaming implemented using an electronic processing system, the method comprising using a computational controller to monitor for the occurrence of a feature awarding event during play of a base game and if a said feature awarding event occurs, awarding an amount of feature credits, and monitoring play of a feature game and decreasing said amount of feature credits dependent on play of the feature game, wherein the method further comprises allowing a player to specify the amount of the credits required to play an activation of the feature game, and if the number of credits required exceeds the number of feature credits available, modifying an award that would otherwise be payable as a result of that activation of the feature game dependent on the proportion of the credits required that are covered by the feature credits that were available.

According to an eighth aspect of the present invention, there is provided a method of gaming implemented using an electronic processing system, the method comprising using a computational controller to monitor for the occurrence of a feature awarding event during play of a base game and if a said feature awarding event occurs, awarding an amount of feature credits, monitoring play of a feature game and decreasing said amount of feature credits dependent on play of the feature game, wherein the method further comprises allowing a player to specify the amount of the credits required to play an activation of the feature game, and deducting credits from a second credit meter to reflect the incremental or total decrease in said amount of feature credits resulting from play of the feature game.

According to a ninth aspect of the present invention, there is provided a method of gaming implemented using an electronic processing system, the method comprising using a computational controller to monitor for the occurrence of a feature awarding event during play of a base game and if a said feature awarding event occurs, awarding an amount of feature credits, monitoring play of a feature game and decreasing said amount of feature credits dependent on play of the feature game, wherein the method further comprises allowing a player to specify the amount of the credits required to play between each activation of the feature game.

In any of the methods described in the immediately preceding paragraphs the second credit meter may be a credit meter that records credits available for play of the base game. The feature game may also be a bought feature requiring the wager of credits which are deducted from the second credit meter.

According to a tenth aspect of the present invention, there is provided a gaming system comprising a game controller for controlling play of a base game and a feature game, at least one display to display game play of the base game and the feature game, and a player interface to enable a player to control at least some aspects of play of the base game and the feature game, wherein during play of the base game, if a feature awarding event occurs, a player is awarded with an amount of feature credits, the feature credits usable to buy bets in the feature game, wherein the gaming system controls use of the feature credits in the feature game in response to inputs received from the player interface and maintains a balance of feature credits as the feature credits are used.

According to an eleventh aspect of the present invention, there is provided a method of gaming implemented using an electronic processing system, the method comprising using a computational controller to monitor for the occurrence of a feature awarding event during play of a base game and if a said feature awarding event occurs, awarding an amount of feature credits, and monitoring play of a feature game and decreasing said amount of feature credits dependent on play of the feature game, wherein the method further comprises allowing a player to specify the amount of the credits wagered in an activation of the feature game.

According to a twelfth aspect of the present invention, there is provided an electronic storage device for communicating with a game controller of the gaming system, the electronic storage device storing instructions to cause a game controller to implement a method of any one of the aspects described in the preceding paragraphs.

According to another aspect of the present invention, there is provided a gaming system operable to play a game comprising a base game and a feature game, the gaming system comprising:

a game controller for controlling play of the game, the game controller awarding base game credits to a player in the event of a winning event during play of the base game, awarding a feature game and feature game credits on the occurrence of a feature awarding event, and awarding feature and/or base game credits in the event of a winning event during play of the feature game.

at least one display to display symbols representing game play of the game, a selection of the symbols available for display including a background symbol,

a main credit meter that maintains a record of the number of said base game credits available to play the base game, and a feature game credit meter that maintains a record of the number of said feature game credits available to a player to play the feature game, and

a player interface to enable a player to select a wager in credits for play of the feature game, the selected wager being deducted from the feature credit meter and/or from the main credit meter,

wherein the amount of feature game credits resulting from the occurrence of the feature awarding event in the base game is related to the background symbol(s) displayed when the feature awarding event occurred.

The amount of feature game credits resulting from the occurrence of the feature awarding event in the base game may be determined by the background symbols displayed when the feature awarding event occurred and the amount of wager placed in the base game when the feature awarding event occurred.

The amount of feature and/or base game credits resulting from the occurrence of the winning event during play of the feature game is determined by the background symbols displayed when the winning event occurred in the feature game and the amount of wager placed in the feature game when the winning event occurred.

The background symbols may be playing card symbols on the display.

Further aspects of the present invention will become apparent from the following description, given by way of example only and with reference to the accompanying drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1: shows a flow diagram of a process according to one embodiment of the present invention for implementation by a gaming system.

FIG. 2: shows a flow diagram of a process to calculate a modified prize as part of the process shown in the flow diagram of FIG. 1.

FIG. 3: shows very diagrammatically an example screen display that may be displayed in accordance with an embodiment of the present invention that has a spinning reel feature game.

FIG. 4: shows a block diagram of a gaming system suitable for implementing the present invention.

FIG. 5: shows diagrammatically a view of a gaming machine suitable for implementing the present invention.

FIGS. 6A and 6B: show exemplary screen displays presenting the results of a game play according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to gaming systems and game methods incorporating a base game and a feature game. The present invention may provide increased flexibility in the way that a player may play a feature game as well as offer further or alternative advantages over gaming systems with feature games at present.

FIG. 1 shows a flow diagram of a process that may be performed by a gaming system in accordance with one embodiment of the present invention. The process may be implemented on any suitable gaming system, including a standalone gaming machine, a networked gaming machine or a gaming system with distributed components.

One or more displays may be used to communicate game information to a player of the gaming system, with the displays either used independently to display different parts of the gaming process (e.g. one screen displaying play of a base game and another displaying play of a feature game), or used together so as to provide game representations over two or more screens.

Those skilled in the relevant arts will appreciate that there are a number of different types of architectures of gaming systems in which the present invention may be implemented with the use of appropriate computational instructions, which may be in software, firmware and/or hardware. Those skilled in the relevant arts will also appreciate, after reading the game process described herein, how to implement the present invention in such architectures, including forming said instructions and building a gaming system to execute the instructions.

Throughout this specification, the term “credit” is used in its normal sense of a tradeable value unit, tradeable in the sense that a player wagers one or more credits when playing the base game or, in the case of the present invention, the feature game. Credit may or may not have an equivalent redeemable amount in real currency. The term “feature credit” is accordingly used for credits that are usable in a feature game. However, unlike credit, it will usually not be possible to cash out feature credit.

In addition, the term “credit meter” as used herein has its ordinary meaning. However, those skilled in the relevant arts will appreciate that should the relevant regulations allow it, an equivalent to a credit meter may be used.

For clarity, for the remainder of this description a credit meter used in association with play of a game in the gaming system of the present invention will be called the “main credit meter” and a credit meter used in association with play of a feature game part of a game will be called the “feature credit meter”.

Those skilled in the relevant arts will appreciate that in a gaming system implemented in accordance with the present invention further credit meters may be necessary to comply with the applicable regulations. In addition, further credit meters may be provided for additional aspects of a game.

After the process starts and all necessary components of the gaming system have been initialized, step 1 involves monitoring for a player of the gaming system to place a bet of an amount of credits in a base game. Once a bet has been placed, an activation of the base game is played according to the bet that was placed (step 2), including deducting the bet from the main credit meter. The base game, for example, may be a spinning reel game in which symbols are spun up onto reels and winning combinations are certain combinations of symbols appearing along a bought pay line defined across the reels. Many alternative games suitable for use as a base game are known and may be developed, including card games, dice games, pick-a-box games and others. For clarity, unless specifically stated otherwise, the following description assumes that a spinning reel game has been selected as the base game.

In step 3, the gaming system evaluates any prizes that are payable as a result of step 2, according to the standard pay table, and taking into account the bet that was placed by the player. For example, the player may have made a multi-part bet that resulted in play of a certain number of pay lines in a multi-line spinning reel game and also bet a certain number of credits per line. Therefore, in this example, the gaming system evaluates each pay line that has been bought by the bet for the existence therein of one of a number of predetermined combinations of symbols. The gaming system then looks up the pay table to identify the award associated with any combinations that have been spun up on a bought pay line and adds the awards together if there are more than one. The award(s), in the form of credits, are then typically added to a win meter and may be varied or eliminated in one or more further gaming events before being credited to the main credit meter.

In step 4, the gaming system determines whether a feature has been triggered. If not, the process returns to step 1 and play of the base game continues. A feature game may be triggered by any one of a number of different events. Examples include the spinning up of a certain combination of symbols in the base game, the reaching of a certain amount in an accumulated total, which may be dependent on amounts bet, amounts won or lost, based on a random number generator or based on some other variable. Other examples of suitable trigger events will be known to those with knowledge of the field of gaming system design, including the applicant's Cashman™ and Hyperlink™ systems.

One trigger event that at least some embodiments of the present invention are suited to implementing, is a trigger event that occurs with equal probability regardless of the size of the wager placed by a player in an associated activation of the base game. An example of this type of trigger is one where, say three special symbols are displayed anywhere on the display (a “scatter”), so that the trigger event may occur whether the player has bought one pay line, all possible pay lines, or any number in between.

Play of an embodiment of a feature game will now be described with reference to steps 5 to 15 of FIG. 1. The feature game described is a spinning reel game, which is a common format of a feature game when the base game is also a spinning reel game. However, the feature game need not be a spinning reel game and in some embodiments of the present invention need not have the same format as the base game, although the feature game may still provide an ability to make a variable multi-part bet (i.e. betting on a selected number of a plurality of different possibilities, each of which could result in a win) in each activation of the feature game. One example of an alternative feature game that may be used is a multiple hand poker-style card game, where the player can use feature credits to buy more hands in the card game and optionally also vary the feature credits bet per hand.

If a feature game has been triggered, the process proceeds to step 5, which involves displaying to the player a number of feature credits that have been awarded to the player and allocated to a feature credit meter due to the triggering of the feature. In the preferred embodiment as presently contemplated, the number of feature credits awarded is the number of credits that would have been required to play a certain number of games at the level of bet that was played when the feature was triggered.

For example, it is common practice to award 15 feature game activations in a feature event. In this case, if in the activation of the base game that triggered the feature, the player bet nine credits in order to play nine lines at one credit per line, then to provide equivalent or approximately equivalent value to the player the awarded feature credits would be 135.

More generally, in this embodiment the awarded feature credits are a multiple of the amount of credits bet in the relevant base game, which could itself be a feature game triggered from a base game associated with that game. The multiple may advantageously be between ten and thirty inclusive. Optionally, the multiple may be dependent on the trigger event. For example, a feature that awards feature credits of 15 times the bet may be triggered by the spinning up of three special symbols and a feature that awards feature credits of 20 times the bet may be triggered by the spinning up of four special symbols.

If in step 4 it was determined that a feature game was not triggered, then the process returns to step 1. Alternatively, the process may branch off to another game process. For example, in addition to a feature game of the type described herein, the gaming system may offer a feature game where the bet size is fixed.

In step 6, the gaming system waits for the player to place a bet using the awarded feature credits. In the preferred embodiment as presently contemplated the gaming system requires the player to immediately play the awarded feature credits in the feature game and continue activations of the feature game until the feature credits have been exhausted and this embodiment is represented in FIG. 1.

Alternatively the gaming system may store at least some of the awarded feature credits, allowing the player to continue playing the base game until they wish to use some of the awarded feature credits for a feature game. The gaming system may allow the player to accumulate feature credits over multiple trigger events of the feature game. In this alternative embodiment, the player may indicate to the gaming system their intention to play a feature game by using a player interface to the gaming system.

If the awarded feature credits are a multiple of the amount bet in a play of the base game and the feature game uses the same bet options as the base game, then it follows that it is always possible, at least at the outset of the feature game, to use all the feature credits in the feature game. If the feature game includes an ability to bet a single credit, then no matter how the player chooses to play the feature credits, they will always be able to exhaust the feature credits.

Where the base game and feature games have the same format, for example both spinning reel games with alike reels (although the reels could also be changed), the gaming system may change the display to indicate that the game currently being played is a feature game. For example, the background to the spinning reels may be changed to different representations or to a different color scheme.

After the player places a bet using the awarded feature credits, the gaming system reduces the balance of the feature credits in the feature credit meter (step 7). If the gaming system is one in which the feature game is a bought feature game, the main credit meter is also deducted by the applicable amount according to the game rules (step 8), typically an equivalent amount.

In the feature event, an enhanced pay table may be used over the base game to provide an increased payout. Alternatively, there may be an increased chance of winning in the feature event, additional wins provided and/or play of the game enhanced in some other manner. The number of feature credits may still be calculated dependent on the relevant bet in the base game activation, preferably as a multiple of the bet.

In a bought feature game a player purchases play of the feature game using credits from both the main credit meter and the feature credit meter. The feature game and main game credit meters are preferably deducted at the same time with each activation of the feature game, although this is not essential and the main game meter may be deducted at a different time to the feature game meter while maintaining the same overall effect. In this embodiment the feature game again preferably continues until all the feature credits have been exhausted. An important result of this embodiment is that the player is provided with increased flexibility in playing a bought feature game, while still maintaining a required return to player.

This addresses the problem of a lack in flexibility, which the Applicant has identified in bought game features. Players that do not fully understand the way the feature works tend to cash out when they get a feature trigger due to the large feature prize, and new players may then not want to play the machine because the fixed bet for the feature is not at a level that they want to play at.

The aspects of step 8 of implementing a bought feature game may not comply with the regulations of some jurisdictions or may not be required for a particular design of gaming system and those skilled in the relevant arts will appreciate that these aspects of step 8 can be readily omitted from the process implemented by a gaming system according to the present invention, as indicated by the dashed line between steps 7 and 9 in FIG. 1.

A second aspect of step 8 is to reduce the main credit meter if the player wishes to bet an amount in an activation of the feature game that exceeds the amount of feature credits available. The main credit meter is reduced by the amount of the shortfall. If there is no shortfall and the feature game is not a bought game, zero credits are deducted from the main credit meter and the process may proceed directly from step 7 to step 9. When credits from the main credit meter are required to meet a shortfall, the gaming system may optionally display a message to the player confirming that they wish to use credits from the main credit meter to supplement the shortfall and inform the player of the amount that will be deducted from the main credit meter. The player may be given an option to change the bet and the gaming system may suggest a bet that can be made within the value of feature credits available. If this second aspect of step 8 is provided the base game and feature game may have the same format (e.g. both spinning reel games with identical reels), which may enable an apparent seamless change between the feature game and the base game.

During the feature game, the gaming system determines the bets that can be made when the feature credits are added with the credits in the main credit meter and only these bets are made available to the player of the gaming system. If there are insufficient credits, the gaming system may invite the player to increase the credits in the main credit meter, for example by inserting their player card to transfer credits into the gaming system.

In step 9, the gaming system plays an activation of the feature game according to the bet that was placed by the player in step 6. As described herein above, often the feature game has the same or similar visual format as the base game, but uses feature credits in addition to credits from the main credit meter or other player account (or uses feature credits instead of credits where the feature comprises free games). The feature game may offer increased chances of winning by, for example, substituting reel symbols or entire reels with more favorable symbols or reels, by doubling, tripling or otherwise increasing the wins paid, or otherwise.

In some embodiments of the present invention, certain events in the feature game may lead to an award of further feature credits, which can be used (wagered) in further feature game activations.

In step 10, the gaming system evaluates whether the feature credits are greater than zero. If so, the gaming system awards any prize that is payable due to the last activation of the feature game (step 11) and then monitors for a further bet of the awarded credits (step 6). If the awarded credits are not greater than zero, the process proceeds to step 12. The awarded credits may be allocated to a win meter and subsequent wins in the feature game added to the win meter. At the conclusion of the feature game and any subsequent game events that may be provided, the win meter may be added to the main credit meter and then reset to zero.

In step 12, the gaming system evaluates whether the feature credits now equal zero. If so, the gaming system awards to the win meter, in a similar process to that of step 11, any prize that is payable due to the last activation of the feature game (step 13), removes the notification to the player that they have feature credits available, including changing the display back to the display for play of the base game if the display was varied to indicate play of the feature game (step 14) and then returns back to step 1. If the awarded credits do not equal zero, then the process proceeds to step 15.

If the process reaches step 15, then more credits were bet in the last activation of the feature game than were available in feature credits. One option to deal with this would be to identify this before the activation of the feature game and require either a reduction in the amount bet to the remaining feature credits or less, or require the feature credits to be held and played at a later time, when perhaps further feature credits have been awarded.

In one embodiment, an alternative way of dealing with this situation is provided. The gaming system allows the player to make a bet in the feature game that exceeds the feature credits available. As previously described, the shortfall is deducted from the main credit meter (step 8). If there is no shortfall and the game is not a bought game, then the process proceeds from step 7 to step 9 without changing the value of the main credit meter.

If the feature game provides an increased chance of winning and/or provides larger prizes, and credits from the main credit meter are available for use in the feature game, the pay ratio of the gaming system may be changed by a player by using a large amount of credits from the main credit meter in the feature game. If this is unwanted, which is anticipated for most, if not all, implementations of the present invention according to this embodiment, then to avoid this situation, step 15 involves paying to the win meter a modified prize.

In the preferred embodiment of the present invention as presently contemplated, determining the modified prize involves the steps shown in FIG. 2. In step 150, the gaming system determines what proportion of the bet was made up of feature credits. In step 151 the prize that would be payable if all the credits were feature credits is determined and in step 152 the prize that would be payable if all the credits were normal credits is determined. The modified prize is then the sum of:

a) the proportion of the bet that was feature credits multiplied by the amount determined in step 152; and

b) the proportion of the bet that was normal credits multiplied by the amount determined in step 153.

When the calculation of the credits to be awarded does not result in an integer number, then the awarded credits may be rounded up or down to an integer.

Therefore, if the feature game provided for example, that all prizes were multiplied by three, then if the bet consisted of 10 feature credits and 10 normal credits, then the effect of step 15 would be to pay twice the winnings that would be won according to the base game pay table or two-thirds of the total winnings that would have been won if the feature activation had used only feature credits.

An example of a bought feature game in accordance with this embodiment of the present invention will now be described with reference to the example screen display S shown in FIG. 3. In the screen display S five spinning reels 50-54 are shown, each displaying three symbols.

The credits available in the main credit meter are displayed in credit display 55, the credits bet placed in the current activation of the game are displayed in bet display 56 and the win resulting from the last activation of the game is displayed in win display 57. In addition, the feature credits available in the feature credit meter are displayed in feature credit display 58 and a feature message 59 informs the player that an enhanced play characteristic is in effect, in this case all wins being multiplied by three. The feature credit display 58 and feature message 59 may only be displayed during play of the feature game.

The player first plays a spinning reel base game having three rows and five columns in the same format as that shown in FIG. 3. In the base game, for example, the spinning up of three or more scattered DIAMOND symbols results in the award of a feature game. On the triggering of the feature game, the gaming system awards the applicable award to the player for spinning up the three or more scattered DIAMOND symbols and adds this to the main credit meter. In addition, the gaming system awards a number of feature credits.

The number of feature credits awarded is somewhat arbitrary, depending on the particular design requirements for each individual game, but as described herein above is preferably a multiple or at least a function of the total bet placed in the triggering feature game. This may maintain a required return to player. The awarded feature credits may be, for example, 300 credits, representing a total bet in a triggering game of 20 credits multiplied by 15.

In the next bought game the player may change the bet and bet, for example, 3 credits per line and 20 lines. The player may achieve this by using the user interface 107 (see FIG. 4), which may be in form of a bank of buttons 22 (see FIG. 5).

In a preferred embodiment of the present invention as presently contemplated the player can change bets in successive activations of the feature game in the same manner as bets are changed in successive activations of the base game. For example, in a spinning reel game the player can simply depress one button to indicate the number of lines to be played and another button to indicate the number of bets per line. This may provide the advantages of increased flexibility in the feature game, ease of use and provide a relatively seamless interface between the feature game and base game.

In accordance with the changed bet, sixty credits are then deducted from both the main credit meter and the feature credit meter. The combination of symbols shown in FIG. 3 is spun up. FIG. 3 shows very diagrammatically a screen shot of the game at this point of the game, where it can be seen that the player has 850 credits in the main credit meter, has bet sixty credits in the current bought feature game and has won 405 credits (see herein below) in the feature game. The player has 240 feature credits left, having used sixty feature credits in the last activation of the feature game.

If the pay table of the game specified that spinning up two scattered DIAMOND symbols resulted in a scorecard prize of 2, then the award would be 360, being the product of the scorecard prize, total bet and feature game multiplier (3 in this example). If the spinning up of three Q symbols also resulted in a scorecard prize of 5, then the award would be 45, being the product of the scorecard prize, bet per line and feature game multiplier. Therefore, the total win of 405 is awarded. The player had 505 credits in the main credit meter at the commencement of the feature game, and after this first activation of the feature game the credit meter is increased to 850 (assuming the awarded credits have not been varied in an intermediary feature game), being the sum of the previous value of the credit meter and the total win, less the amount of the feature bet.

After one or more further activations of the feature game the player now has only 10 feature credits left. As described in more detail previously herein, in a currently contemplated preferred embodiment, the player is still able to bet more than the available feature credits. Alternatively, they may be limited to a bet of 10 feature credits or less.

In this example, in the next bought game the player bets 20 credits to play 20 lines at one credit per line, so that half the credits are covered by feature credits from the feature credit meter and half the credits are covered only by credits from the main credit meter. Accordingly, half any win, being the proportion of feature credits used to cover the bet, is multiplied by three. For the purposes of example only, if the reels stopped in the same position as shown in FIG. 3, then the total award is 90 credits. This award represents the following calculation steps:

a) The scorecard prize of 2 for the two DIAMONDS multiplied by the total bet of twenty to give 40 credits;

b) The scorecard prize of 5 for the three Q's multiplied by the bet per line of one to give 5 credits;

c) The total win is therefore 45 credits, half of which is multiplied by three and added to the other half to result in 90 credits.

If the feature game allows further feature credits to be won, then a further win meter may be provided, or the feature credit display 58 incremented directly in accordance with the win. A pop-up message or other notification may report the win of feature credits and the amount won. The winning of further feature credits may result from the occurrence of a winning combination, which may or may not also be a winning combination for the purposes of awarding credits to the win meter 57 and/or may result from another game event, for example the reaching of a randomly selected value for turnover of plays in the feature game.

FIG. 6A shows a partial screen shot of play of the base game on the occurrence of a feature trigger event. The game is a spinning reel game and only the window in which the reels are displayed is shown in FIG. 6A. In other words, other display items such as a credit display, bet display, win display and pay line indicators have been omitted from FIG. 6A. The game shown in FIG. 6A is a spinning reel game with five reels 60-64, each displaying four symbol positions 65-68 on the display. In the embodiment shown the five reels 60-64 thus define five columns and the four symbol positions 55-58 thus define four rows that resulted from spinning the reels.

As illustrated in FIG. 6A, the selection of 20 symbols is made from a collection of previously defined symbols, being the symbols on the reels 60-64, and displayed in the symbol positions in the normal manner for a spinning reel game. A trigger event for a feature game may include the occurrence of scattered symbols in the window (i.e. a predefined minimum number of a certain symbol or a certain combination of symbols occurring in any of the 20 symbol positions), the occurrence of a certain number of wild symbols in the window, or the occurrence of certain background symbols in the window. Other trigger events may be used. The collection of symbols in FIG. 6A includes one or more special symbols 69. In this example, one special symbol has been spun up on each of the spinning reels 60-64 which triggers a feature game that includes the award of a number of feature credits.

Some symbols on the reel strips 60-64 have a playing card symbol as a background symbol 70. The amount of feature credits awarded depends on the strength of the poker hand determined by the playing card symbols in the outcome of the base game in FIG. 6A. For example, if playing card symbols on the reels give a Royal Flush (in the example shown the Ace, King, Queen, Jack and 10 of spades), this may award a starting pool of 2000 feature credits. Lesser value hands may result in a lesser value award of feature credits to the starting pool. The amount of feature credits may also be determined by the strength of the poker hand displayed and the wager placed in the base game when the feature awarding event occurred. The variation in starting pool may be in line with the probability of occurrence of the poker hand.

The occurrence of the trigger event may always result in the award of some feature credits. For example, there may be a minimum award of 100 feature credits. The existence of a ‘winning’ poker hand in the background symbols may cause the award of feature credits to be increased, dependent on the hand that was achieved. Alternatively, if the trigger event occurs and not ‘winning’ poker hand has occurred in the background symbols, if any, that have been displayed, then no award of feature credits may be made and the feature may not be triggered.

In a similar manner to that described above in relation to FIGS. 1 to 3, the players may determine how much of the feature credits they want to bet at each spin of the feature game. For example, if the player received 2000 feature credits from a royal flush in the base game, he/she may now decide to stake 1000 feature credits per spin for the next feature game.

An exemplary result of a further play is displayed in FIG. 6B. The award from the feature game can be determined by the stake multiplied by the award, if any, that resulted from the feature game. The foreground symbols may indicate the award, if any, payable from that game play of the feature game. If background symbols are used, they may in one embodiment also be provided during play of the feature game and may cause the award of a prize in the feature game if they occur in a certain combination. For example, if the player spins a flush as displayed by background symbols 71 in FIG. 6B (2, King, 4, Jack, and 10 of Spades), the award would be the flush prize e.g. 1000 multiplied by the stake (1000), resulting in 1,000,000 credits, which may be added to a win meter and transferred to the credit meter when the feature game has been concluded. Otherwise, the background symbols may not be displayed or may not result in any award during the feature game, in which case the foreground symbols only are used to determine the awards from the feature game.

In some embodiments, during play of the feature game, it may be possible to win an additional award of feature credits. The award of additional feature credits may be indicated by a particular combination of either foreground or background symbols, or as a combination of both foreground and background symbols. One example of the use of background symbols may be a re-occurrence of the same event that triggered the feature game, which may result in a repeat award of feature credits. The repeat award may in one embodiment be constrained to the same amount as that which was first awarded when the feature game was triggered from the base game. Alternatively, it may be a function of the particular trigger event that occurred in the feature game (where there is more than one possible trigger event) and/or on the amount of feature credits that were wagered in the game play of the feature game that the trigger event was associated with.

Each time the player spins the reels and places a stake, the stake is reduced from the feature credit pool until the starting pool is reduced to zero. In the above example, the feature credit pool is first reduced by 1000 (the stake), leaving 1000 for the next spin(s).

In an alternative embodiment, the trigger event for the feature game may be the occurrence of a winning poker hand in the background symbols, so that the background symbols perform the dual role of triggering the feature and determining the award of feature credits for the feature game. Also, background symbols other than those suitable for forming poker hands may be used.

In the description of the embodiment shown in FIGS. 6A and 6B only feature credits were wagered in the feature game. In an alternative embodiment, the feature may be a bought feature, requiring the player to wager both feature credits and normal credits during the feature game. For example, the player may have to wager an equivalent amount of both feature credits and normal credits in order to play each game play of the feature game, which again ends when all feature credits have been used.

FIG. 4 shows a block diagram of a gaming system, generally referenced by arrow 100, suitable for implementing the present invention. As described previously, the gaming system 100 may be, for example, a standalone gaming machine, a networked gaming machine or have distributed components.

The gaming system 100 may include a game controller 101, which in the illustrated example includes a microprocessor, microcontroller, programmable logic device or other computational device 102. Instructions and data to control operation of the computational device 102 are stored in a memory 103, which is in data communication with the computational device 102. Typically, the gaming system 100 will include both volatile and non-volatile memory and more than one of each type of memory, with such memories being collectively represented by the memory 103. In addition, the functions of the computational device 102 may be separated into separate devices. The instructions to cause the game controller 101 to implement the present invention will be stored in the memory 103.

The gaming system may include meters 104 for the purposes of regulatory compliance. The main credit meter described herein above may be maintained in the meters 104. Subject to regulatory compliance, the feature credit meter and/or win meter may be implemented in non-volatile RAM instead of in the meters 104. The gaming system also includes input/output ports 105 for communicating with the peripheral devices of the gaming system 100. In FIG. 1, the peripheral devices that communicate with the controller are one or more displays 106, user interfaces 107, card readers 108, printers 109, a bill acceptor and/or coin input 110 and a output mechanism 111.

In addition, the gaming system 100 may include a communications interface, for example a network card 112 to communicate with a network for such purposes as sending status information, accounting information and the like to a central controller, allowing communication from the central controller to the gaming system 100 or for other purposes. In one embodiment, the network card 112 and I/O interface 105 may be implemented in a single machine communications interface.

In embodiments where a player is able to store feature credits for later use, the gaming system may provide functionality to allow the player to store the feature in a player account. The player account may be located in remote memory, with the gaming system 100 communicating the feature credits together with a player identifier read from a player tracking card or otherwise obtained, to be stored using the network card 112. The player account may instead be stored on the player tracking card itself. A game identifier may also be stored associated with the balance of feature credits, so that the gaming system can separate feature credits from different games and prevent or restrict feature credits from one game being used in another game. For example, the feature credits may be only able to be used for play of the same game in which they were won. Alternatively, the feature credits may be usable for a class of games having the same or similar play characteristics for the feature game in terms of the expected pay ratio.

Referring now to FIG. 5 of the accompanying drawings, a gaming machine generally referenced by arrow 30 is shown. The gaming machine 30 is an example of a gaming machine that is suitable to implement the present invention. Although the gaming system shown in FIG. 4 may be a gaming machine of the type shown in FIG. 5, different reference numerals are used in FIG. 5 for components that may be equivalent to those shown in FIG. 4 to reflect that the gaming system 100 may not be in the form of a gaming machine.

The architecture of the gaming machine 30 includes a console 32 having a display 34 on which is displayed representations of a game 36 in accordance with the present invention, that can be played by a player. A mid-trim 20 of the gaming machine 30 houses a bank of buttons 22 for enabling a player to play the game 36. The mid-trim 20 also houses a credit input mechanism 24 including a coin input chute 24A and a bill collector 24B. A top box 26 may carry artwork 28, including for example, pay tables and details of bonus awards and other information or images relating to the game. Further artwork and/or information may be provided on the front panel 29 of the console 32. A coin tray 38 is mounted beneath the console 32 for cash payouts from the gaming machine 30.

The display 34 shown in FIG. 5 is in the form of a video display unit, particularly a cathode ray tube screen device. Alternatively, the display 34 may be a liquid crystal display, plasma screen, any other suitable video display unit, or the visible portion of an electromechanical device. The top box 26 may also be a display, for example a video display unit, which may be the same type as the display 34, or a different type of display.

Those skilled in the relevant arts will appreciate that modifications and additions may be made to the present invention without departing from the scope of the invention.

Where in the foregoing description reference has been made to integers having known equivalents, then those equivalents are hereby incorporated herein as if individually set forth.

It will also be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

It will also be understood that the term “comprises” (or its grammatical variants) as used in this specification is equivalent to the term “includes” and should not be taken as excluding the presence of other elements or features. 

1. A gaming system operable to play a game comprising a base game and a feature game, the gaming system comprising: a game controller for controlling play of the game, the game controller awarding base game credits to a player in the event of a winning event during play of the base game and awarding a feature game and feature game credits on the occurrence of a feature awarding event during play of the base game, at least one display to display representations of play of the game, a player interface to enable the player to control at least some aspect of play of the base game and the feature game, a main credit meter that maintains a record of the number of said base game credits available to play the base game, a feature game credit meter that maintains a record of the number of said feature game credits available to a player to play the feature game, and a selector that enables the player to select a wager in credits from a plurality of wager options of different values for play of the feature game, the selected wager being deducted from the feature credit meter, and wherein the main credit meter is also deducted in response to play of the feature game.
 2. The gaming system of claim 1, wherein the main credit meter is deducted in response to play of the feature game by an amount of credits equal to the value of the wager selected for that play of the feature game.
 3. The gaming system of claim 1 or claim 2, wherein the feature game has an enhanced play characteristic in comparison to the base game.
 4. The gaming system of claim 3, wherein the enhanced play characteristic is at least one of an enhanced pay out table and an increased chance of a win.
 5. The gaming system of claim 1, wherein the game controller requires play of the feature game and wagering of the feature game credits immediately following the award of the feature game.
 6. The gaming system of claim 1, wherein the feature game credits can not be cashed out and wherein if a player cashes out and there is a positive balance of feature game credits, the gaming system allows play of the feature game, including by a subsequent player of the game.
 7. The gaming system of claim 1, wherein the number of awarded feature game credits is a multiple of the bet made in the game play of the base game that caused the feature game to be awarded.
 8. The gaming system of claim 7, wherein the multiple is between 10 and 30 inclusive.
 9. The gaming system of claim 7, wherein a plurality of different events cause the award of a feature game and feature game credits and a plurality of different multiples of said bet made are awardable, wherein the applicable multiple is dependent on the event that caused the award of the feature game.
 10. The gaming system of claim 1, wherein the plurality of wager options comprises wager options with a different number of bets and different amounts wagered per bet.
 11. A gaming system comprising a game controller for controlling play of a base game and a feature game, at least one display to display game play of the base game and the feature game, and a player interface to enable a player to control at least some aspects of play of the base game and the feature game, both the base game and the feature game resulting in the award of an award on the occurrence of a winning event for that game, wherein during play of the base game, if a feature awarding event occurs, a player is awarded with an amount of feature credits, the feature credits usable to buy bets in the feature game, wherein the gaming system controls use of the feature credits in the feature game in response to inputs received from the player interface and maintains a balance of feature credits as the feature credits are used, and wherein should more credits than the current balance of feature credits be required to play the feature game, credits are deducted from a second credit meter dependent on the difference between the required credits and the feature credits.
 12. The gaming system of claim 11, wherein if credits are deducted from the second credit meter, then a modified award is awarded, dependent on the proportion of the bet covered by feature credits.
 13. A gaming system comprising a game controller for controlling play of a base game and a feature game, at least one display to display game play of the base game and the feature game, and a player interface to enable a player to control at least some aspects of play of the base game and the feature game, both the base game and the feature game resulting in the award of an award on the occurrence of a winning event for that game, wherein during play of the base game, if a feature awarding event occurs, a player is awarded with an amount of feature credits, the feature credits usable to buy bets in the feature game, wherein the gaming system controls use of the feature credits in the feature game in response to inputs received from the player interface and maintains a balance of feature credits as the feature credits are used, and wherein should more credits than the current balance of feature credits be required to play the feature game, then an award resulting from that play of the feature game is modified.
 14. The gaming system of claim 13, wherein the extent of modification is directly dependent on the proportion of the bet covered by feature credits.
 15. The gaming system of claim 11, wherein the amount of feature credits awarded is dependent on the value of a bet placed by the player in an activation of the base game that is causally linked to the award of the feature credits.
 16. The gaming system of claim 15, wherein the multiple is between 10 and 30 inclusive.
 17. The gaming system of claim 11, wherein following award of the feature credits the gaming system requires immediate play of the feature game and requires that all the feature credits are used before returning to the base game.
 18. The gaming system of claim 17, wherein the feature credits can not be cashed out and the requirement to play the feature game until all the feature credits are used continues when play of the game is recommenced following a player cashing out.
 19. The gaming system of claim 11, wherein the probability of occurrence of the feature awarding event is independent of the size of a bet placed in an activation of the base game.
 20. The gaming system of claim 11, wherein the feature game is a bought feature game.
 21. The gaming system of claim 20, wherein the base game and the feature game have the same format and an equal number of credits are deducted from a main credit meter as the number of feature credits bet in the feature game.
 22. A gaming system comprising a game controller for controlling play of a game comprising a base game and a feature game, at least one display to display game play of the game, and a player interface to enable a player to control at least some aspects of the game play of the game, both the base game and the feature game resulting in the award an award if a winning event occurs, wherein during play of the base game, if a feature award event occurs, a player is awarded with an amount of feature credits, the feature credits usable to buy bets in the feature game, wherein the feature game repeats over consecutive activations and for each said activation the game controller allows the player to control use of the feature credits in said feature game by operating the player interface.
 23. The gaming system of claim 22, wherein the game controller repeatedly activates the feature game until the feature credits have been exhausted and then returns to play of the base game.
 24. The gaming system of claim 22, wherein the base game and the feature game have the same screen format and have the same bet options.
 25. A gaming system adapted to play a game comprising a base game and a feature game, the gaming system comprising: a game controller for controlling play of the game and adapted to award base game credits to a player in the event of a winning play on the base game and activating the feature game and awarding feature game credits on the occurrence of a triggering event during play of the base game, the feature game credits being at least sufficient to enable a plurality of activations of the feature game at a level of bet that was made in the base game when the triggering event occurred, at least one display to display game play of the base game and the feature game, a player interface to enable the player to control at least some aspect of the game play of the base game and the feature game, a main game credit meter adapted to display the number of game credits available to a player to play the game, a feature game credit meter adapted to display the number of feature game credits available to a player to play the feature game, and a selector which, when a player is awarded a feature game by the game controller, enables the player to select the number of feature game credits to be bet on a play of the awarded feature game.
 26. The gaming system of claim 25, wherein the feature game must be played after the triggering event before the game controller controls the game to return to play of the base game and all the feature credits must be exhausted before the game controller allows play of the base game to resume.
 27. The gaming system of claim 25, wherein the awarded feature game credits are a predefined multiple of a bet made in the activation of the base game that caused the feature game to be awarded.
 28. The gaming system of claim 25, wherein the selector allows the player to vary the number of feature game credits to be wagered between successive plays of the feature game.
 29. The gaming system of claim 25, wherein the player can vary the number of feature game credits to be wagered between successive activations of the feature game by varying at least one of the number of bets made in each said successive play and the amount wagered per bet.
 30. The gaming system of claim 25, wherein the gaming system offers an option to buy a bet in the feature game that has a value of one credit.
 31. The gaming system of claim 25, wherein the gaming system is a standalone or networked gaming machine.
 32. A gaming system operable to play a game comprising a base game and a feature game, the gaming system comprising: a game controller for controlling play of the game, the game controller awarding base game credits to a player in the event of a winning event during play of the base game, awarding a feature game and feature game credits on the occurrence of a feature awarding event, and awarding feature and/or base game credits in the event of a winning event during play of the feature game. at least one display to display symbols representing game play of the game, a selection of the symbols available for display including a background symbol, a main credit meter that maintains a record of the number of said base game credits available to play the base game, and a feature game credit meter that maintains a record of the number of said feature game credits available to a player to play the feature game, and a player interface to enable a player to select a wager in credits for play of the feature game, the selected wager being deducted from the feature credit meter and/or from the main credit meter, wherein the amount of feature game credits resulting from the occurrence of the feature awarding event in the base game is related to the background symbol(s) displayed when the feature awarding event occurred.
 33. The gaming system of claim 32, wherein the amount of feature credits resulting from the occurrence of a winning event in the base game is determined by the background symbols displayed when the feature awarding event occurred and the amount of wager placed in the base game when the feature awarding event occurred.
 34. The gaming system of claim 32, wherein the amount of feature and/or base game credits resulting from the occurrence of the winning event during play of the feature game is determined by the background symbols displayed when the winning event occurred and the amount of wager placed in the feature game when the winning event occurred.
 35. The gaming system according to claim 32, wherein the background symbols are playing card symbols on the display.
 36. A method of gaming implemented using an electronic processing system, the method comprising using a computational controller to monitor for the occurrence of a feature awarding event during play of a base game and if a said feature awarding event occurs, awarding an amount of feature credits, and monitoring play of a feature game and decreasing said amount of feature credits dependent on play of the feature game, wherein the method further comprises allowing a player to specify the amount of the credits required to play an activation of the feature game, and if the number of credits required exceeds the number of feature credits available, deducting credits from a second credit meter dependent on the difference between the credits required and the feature credits that are available.
 37. A method of gaming implemented using an electronic processing system, the method comprising using a computational controller to monitor for the occurrence of a feature awarding event during play of a base game and if a said feature awarding event occurs, awarding an amount of feature credits, and monitoring play of a feature game and decreasing said amount of feature credits dependent on play of the feature game, wherein the method further comprises allowing a player to specify the amount of the credits required to play an activation of the feature game, and if the number of credits required exceeds the number of feature credits available, modifying an award that would otherwise be payable as a result of that activation of the feature game dependent on the proportion of the credits required that are covered by the feature credits that were available.
 38. A method of gaming implemented using an electronic processing system, the method comprising using a computational controller to monitor for the occurrence of a feature awarding event during play of a base game and if a said feature awarding event occurs, awarding an amount of feature credits, monitoring play of a feature game and decreasing said amount of feature credits dependent on play of the feature game, wherein the method further comprises allowing a player to specify the amount of the credits required to play an activation of the feature game, and deducting credits from a second credit meter to reflect the incremental or total decrease in said amount of feature credits resulting from play of the feature game.
 39. A method of gaming implemented using an electronic processing system, the method comprising using a computational controller to monitor for the occurrence of a feature awarding event during play of a base game and if a said feature awarding event occurs, awarding an amount of feature credits, monitoring play of a feature game and decreasing said amount of feature credits dependent on play of the feature game, wherein the method further comprises allowing a player to specify the amount of the credits required to play between each activation of the feature game.
 40. The method of claim 38, wherein the second credit meter is a credit meter that records credits available for play of the base game.
 41. The method of claim 39, wherein the feature game is a bought feature requiring the wager of credits which are deducted from the second credit meter.
 42. A gaming system comprising a game controller for controlling play of a base game and a feature game, at least one display to display game play of the base game and the feature game, and a player interface to enable a player to control at least some aspects of play of the base game and the feature game, wherein during play of the base game, if a feature awarding event occurs, a player is awarded with an amount of feature credits, the feature credits usable to buy bets in the feature game, wherein the gaming system controls use of the feature credits in the feature game in response to inputs received from the player interface and maintains a balance of feature credits as the feature credits are used.
 43. A method of gaming implemented using an electronic processing system, the method comprising using a computational controller to monitor for the occurrence of a feature awarding event during play of a base game and if a said feature awarding event occurs, awarding an amount of feature credits, and monitoring play of a feature game and decreasing said amount of feature credits dependent on play of the feature game, wherein the method further comprises allowing a player to specify the amount of the credits wagered in an activation of the feature game.
 44. An electronic storage device for communicating with a game controller of the gaming system, the electronic storage device storing instructions to cause a game controller to implement a method according to claim
 36. 